1. Field of the Invention
The present invention relates generally to a system and method for sealing the trailing edge of folded articles, and particularly to a system and method for sealing the trailing edge of folded articles with one or more sealing tabs or stickers to facilitate mailing.
2. Background of Related Art
The United States Postal Service (“USPS”) establishes requirements for articles that are sent through the mail. These requirements ensure that articles of mail received by the USPS can be, for example, sorted in automatic machines without causing jams or other malfunctions. These requirements also ensure that mailed articles can be easily packed, carried, and delivered by postal workers.
Many articles, such as folded self mailers and booklets, are required to be sealed to prevent them from opening and, for example, becoming caught in the aforementioned sorting machines. This is often done by placing a small sticker, or tab, to the edge of the article and folding it over to seal open edges. Conventionally, a tabbing machine is used to apply tabs to folded self mailers. The tabs are then folded and sealed using either a side apply and fold or a leading edge apply and fold method (or “crash” method). The side apply uses a shaped rail to bend the tab over and adhere it to opposite side of the article. A leading edge apply generally blows down a tab on the leading edge of the article as the article passes over a slot in the table of the machine. As the article moves forward, the tab “crashes” into the trailing edge of the slot folding the tab under and adhering it to the article.
The edge fold and crash techniques (or, “conventional techniques”) work well enough for sealing tabs located on the sides and/or leading edge of the article. Recent changes to USPS regulations, however, specify that folded articles must be sealed on up to three open sides (i.e., the fourth side being the fold). See, 39 C.F.R. §111 as amended Sep. 8, 2009. This requires the article to be sealed on the trailing edge.
Using conventional edge fold and crash techniques under this new regime requires the used of multiple tabbing machines. This is because conventional tabbers are unable to seal the trailing edge of an article as it passes through the machine. For example, two tabbing machines using side apply and fold can be used to place tabs on opposite sides as needed based on product flow. Sealing all three sides of the article, however, requires up to three tabbers (e.g., the Kirk Rudy Model # KR535 or KR435) and a product-turning machine (e.g., the Kirk Rudy Model # KR730).
The article passes through the first tabber and is tabbed on one side. The article then passes through a turner that rotates the article 90 degrees (e.g., turning the tabbed edge to the leading edge or the trailing edge). A second tabber can then apply tabs to one of the (now) edges. A third tabber can then apply tabs to the opposite edge. This arrangement avoids a machine from tabbing a trailing edge. Using conventional technology, therefore, the new USPS regulations require two, three, or four machines to be purchased, operated, and maintained to achieve an acceptable product. This represents a significant expense and requires additional floor space on the production floor. A single tabbing machine such as the Kirk-Rudy Model # KR535, for example, costs approximately $20,000. In addition, two, three, or four machines must be recalibrated each time a new product is introduced with a different material, thickness, or size.
What is needed, therefore, is a device that enables tabs to be placed on the trailing edge of a product. The device should be compatible for use with existing technologies to enable an article to be tabbed on three sides without turning or flipping the article. The device should enable an article to be tabbed on at least three sides using a single machine in substantially less space than is occupied by the two, three, or four conventional machines currently required. It is to such a device that embodiments of the present invention are directed.